Question

which of the following fuel gases works well for cutting and brazing, but
a acetylene
b propylene
c ethylene
d propane
e natural gas

Explanation:

Acetylene is a fuel gas that when burned with oxygen in a torch can reach very high temperatures (up to around 3300°C). This high - temperature flame makes it ideal for cutting through metals (as it can melt the metal) and for brazing (where it can heat the base metal and filler metal to the brazing temperature). Propylene, ethylene, propane, and natural gas generally do not produce flames as hot as acetylene for these specific metal - working processes.

Answer:

A. Acetylene